1. Field of the Invention
This invention relates to combustion turbine engines with inter cooling, saturation, recuperation and reheat.
2. Description of Related Art
A typical and currently available simple cycle combustion turbine consists of a compressor for compressing the atmospheric air, a combustor for heating the compressed air, a turbine for power production and an electric generator for converting mechanical energy into electrical energy. A more sophisticated combustion turbine concept with a number of compressors with intercoolers and with a number of turbines with associated combustors and, also, with a recuperator, has been theoretically known at least since the 1920's.
Major features of the conventional, generic combustion turbine concept as disclosed in the article entitled "Optimization of Gas Turbine Cycles with Variable Number of Combustion, Compressor and Intercooler Stages", document no. 81-JPGC-CT-6 published in 1981 by the Americal Society of Mechanical Engineers, are as follows:
The highest pressure turbine with associated combustor has the highest inlet temperature. The lower pressure turbines with associated combustors have the same (as the highest pressure turbine) inlet temperature; PA1 The expansion pressure ratios of all turbines are equal; and PA1 The compression ratios of all compressors are equal
Earlier patents, for example, U.S. Pat. No. 2,584,232 to Sedille utilize this generic theoretical combustion turbine cycle with the aforementioned features. The major thrust of these patents is the utilization of available and otherwise wasted heat resources of the generic theoretical combustion turbine concept for improving the resulting power plant efficiency. These heat resources are used for steam generation and additional electric power production by the bottoming steam turbine or via steam injection.
No practical applications of this prior art theoretical combustion turbine cycle have been established, due to a number of engineering problems facing the power plant designers.
The first and the most important engineering problem is that the highest pressure turbine for the prior art combustion turbine concept has the highest inlet temperature. This presents a serious challenge because of high thermal and transient stresses in the high pressure and temperature turbine components, and requires special materials and engineering yet to be developed.
The second engineering problem is a result of the fact that for a typical prior art concept a plurality of combustion turbines with the same inlet temperatures and equal pressure ratios have very high exhaust gas flow temperatures which are the inlet temperatures for a plurality of downstream combustors. This is yet another serious engineering challenge.
3. Objects of the Invention
An object of this invention is to develop a new combustion turbine with improved efficiency and economics which embodies a properly integrated plurality of turbines with reheat, a plurality of compressors with intercoolers, a recuperator, saturator, water heaters, duct burners, and a heat recovery steam generator.
Yet another object of this invention is an integration of a saturator in the combination turbine concept to improve the combustion turbine thermal efficiency and to increase the specific production of electric power per pound of air. The saturator, via heat and mass exchange, preheats the compressed air and saturates it with moisture before entering a recuperator.
Another object of the invention is to incorporate a recuperator and water heaters into the inventive combustion turbine concept for better utilization of the combustion turbine cycle available heat with associated improvement of the thermal efficiency.
Still another object of the invention is a maximum utilization of the available prior art simple cycle combustion turbine components with the addition of currently available industrial components properly integrated into the inventive cycle in order to facilitate practical implementation of the inventive concept.
Yet a further object of this invention is to provide a heat recovery steam generator for the alternative utilization of the exhaust gas heat, for steam use in the bottoming cycle and/or for steam injection into one of the plurality of turbines.
A further object of the invention is to provide duct burners strategically positioned in locations of the system to improve the efficiency and economics of the system further.